A platinum material exhibiting good high-temperature strength has been used mainly as a structural material for glass melting. High-temperature strength required to the platinum material is so-called creep strength. In particular, it has been the most important objective in developing a platinum material to extend a duration until creep rupture as much as possible.
For improving creep strength in the strengthened platinum, there has been used a technique that a particular oxide is finely dispersed in platinum. A known example of such an oxide-dispersion strengthened platinum material is that in which zirconium oxide is dispersed. For producing a platinum material in which zirconium oxide is finely dispersed in platinum, there have been suggested a variety of processes such as powder metallurgy and internal oxidation.
The previous processes where zirconium oxide is dispersed in platinum can ensure a certain level of creep strength, i.e., a certain level of creep rupture life, but are insufficient to achieve further improvement in creep strength.